In OpenNeuro ds006065, the late SEP difference after theta-synchronized stimulation was not significant and disappeared after background correction

We re-analyzed single-pulse evoked potentials (SEPs) from OpenNeuro ds006065 snapshot 1.0.0 to test whether late hippocampal SEP amplitude (50–250 ms) increased more after theta-trough-synchronized (TS) than phase-blind (PB, 1 Hz) lateral temporal cortex stimulation, and whether the difference reflected evoked or ongoing signal. Across 8 subject-condition units (4 TS, 4 PB), the late single-trial peak-to-peak change was larger after TS (+0.173 log units, about 19%), but the exact permutation test was not significant (p=0.200). The pre-pulse window changed nearly as much (TS−PB +0.137; Pearson r=0.82 with the SEP-window change), and late single-trial amplitude was 0.9–1.3 times the pre-pulse amplitude. After subtracting the pre-pulse change, the monopolar TS−PB difference was +0.036 (p=0.714). In the bipolar analysis, the corrected difference was +0.051 (p=0.800), the single-trial difference +0.033 (p=0.743), and the averaged-SEP difference −0.024 (p=1.000). The monopolar averaged-SEP result showed a trend (+0.324, p=0.086); all single-unit bootstrap confidence intervals included zero. These data are consistent with a change in ongoing monopolar signal amplitude, not a specific change in the evoked response. The analysis used 4 TS and 4 PB units, with p17 and p19 in both conditions; it did not fit the authors’ trial-level mixed model, had low power, used an approximate line-noise filter, left out p20, and did not repeat the cluster-permutation test. A documented argument omission in the deposited authors’ code prevents its p17/p19 PB preprocessing call from running as published. The raw data are not included; the package contains analysis code, results, four figures, and a manifest with keys and hashes for 97 files.

hippocampus · single-pulse evoked potential · theta-synchronized stimulation · phase-blind stimulation · intracranial EEG · background signal · peak-to-peak amplitude · permutation test · OpenNeuro ds006065